The average reported efficacy of 70% was significantly lower than the 94.5% to 95% reported by the other two leading candidates, Moderna and Pfizer.
“[T]The Pfizer vaccine is committed to its initial doses, which go to the European Union and the United States. Moderna’s supplies will be tied to the US at least in the first half of 2021, so in light of that, the Oxford / AstraZeneca vaccine is really good news for the rest of the world, ”Andrea Taylor, Assistant Program Director at Duke Global Health Innovation, told CNN.
AstraZeneca promised to supply hundreds of millions of doses to low- and middle-income countries and to provide the vaccine on a non-profit basis for those countries in perpetuity. The vaccine developed at the University of Oxford in England is much cheaper than the other vaccine, and most importantly, it will be much easier to transport and distribute in developing countries than its competitors because it does not need to be stored in freezing temperatures.
“I think it’s the only vaccine that can be used in those places at the moment,” Azra Ghani, head of infectious disease epidemiology at Imperial College London, told CNN.
“Pfizer and Moderna require freezer storage, and this is not present in many places,” said Ghani.
Cold Chain Cold is the standard storage used worldwide to deliver vaccines from central sites to local health clinics. Ghani added that so far, the AstraZeneca vaccine “is the only one that can definitely be delivered to these systems.”
Vaccines depend on various technologies. AstraZeneca’s offer – like Russia’s Johnson & Johnson and Sputnik V vaccine – uses adenoviruses to transfer genetic parts of the coronavirus to the body.
The Moderna and Pfizer vaccines use pieces of a genetic material called messenger RNA (mRNA) to stimulate the body to make artificial pieces of the coronavirus and stimulate the immune response. “This is a relatively new technology and little is known about the stability of mRNA over time,” Benny Ward, Chair of the Education and Standards Committee at the UK School of Pharmaceutical Medicine, told CNN.
She said it in the name of Moderna and Pfizer Building information and manufacturing capacity, they may be able to find ways to store at higher temperatures, but the Oxford vaccine “has the potential to be able to ship more easily around the world” using existing supply chains.
However, it will only be of value if levels of vaccine efficacy are maintained during deployment in developing countries.
Moncef Salawi, senior advisor for the US government’s Warp Speed Operation, said this week that there are “a number of variables that we need to understand” about the differences in dose and age in the Oxford / AstraZeneca results, and then the ongoing US experience may need to be adjusted.
On Thursday, a spokesperson for AstraZeneca told CNN that they are currently in discussions with the FDA about including a half-strength dosing regimen in their US trials, which currently have about 10,000 participants.
“The simplicity of dispensing the AstraZeneca vaccine could compensate for the low potential effectiveness,” said Ever Ali, Associate Professor of International Business at Warwick Business School.
“The actual effectiveness of more fragile mRNA vaccines in transport and storage may be lower in real-world conditions where it may be difficult to verify the correct storage of each dose,” she added.
BioNTech said last week that it was working with Pfizer to come up with a formula that would allow its vaccine to be stored at record temperatures by the second half of 2021. Moderna this month expanded its estimate of how long its vaccine could be stable in refrigerator temperatures from an estimated seven to 30 days. This, according to Moderna’s chief technical officer and quality officer, Juan Andres, “would enable simpler distribution and more flexibility to facilitate wider vaccination in the United States and other parts of the world.”
Pledge to help
AstraZeneca has pledged 300 million doses of its vaccine to COVAX, a partnership between GAVI, the Vaccine Alliance; World Health Organization; Alliance for Epidemic Preparedness Innovations (CEPI) to ensure equitable distribution to 92 developing countries. The only other known vaccine developer to pledge the same volume is Sanofi, with 200 million doses.
A representative of the Global Alliance for Vaccines and Immunization told CNN that the Vaccine Institute of India (SII) and the Bill and Melinda Gates Foundation will also provide up to 200 million doses of AstraZeneca and / or Novavax candidate vaccines for low-income countries. Moderna and Pfizer have not pledged any dosages for COVAX.
“[AstraZeneca has] You’ve been working with the manufacturing experts in this alliance to help get a variety of different manufacturing sites, and of course it’s not just the vaccine itself, it’s also the glass vials it goes into, the stoppers that go over the bottles, and the syringes, Ward said.
An Oxford University spokesman told CNN: “Our vaccine can be rapidly deployed in the current health conditions, which will help stop the further spread of this disease as we learn more and more about how to prevent and treat it.” He added that a group of vaccines would be needed, and some of them could be more effective for different ages and populations.
He said, “The key with any vaccine is that it can affect public health, including how quickly it can be distributed. We can be quickly and easily distributed around the world, using existing logistics services, and easily stored in the refrigerator.”
However, Ghani warned that the 20% “was not close to the ideal – about 70% – that we would like to see so that we can achieve herd immunity, so some countries will still fall short.”
Duke’s modeling shows that while wealthier countries may have purchased billions of doses up front to increase their chances of covering their populations, the developing world will depend entirely on COVAX.
Bill Gates said that the solution “does not expose the shame of the rich countries that do the natural thing of wanting to protect their people,” rather, it was to greatly increase their manufacturing capacity.
Stephen Evans, professor of pharmacological epidemiology at the London School of Hygiene and Tropical Medicine, cautioned that monitoring efficacy and safety issues will be an ongoing challenge in the developing world.
He told CNN: “There may be some negative effects that may only appear in those low- and middle-income countries; they have different diets, different levels of nutrition in general, and different characteristics.”
While the Oxford vaccine may have special promise at this point to help low-income countries, there are still many caveats about the data that must be resolved before it is even released.
Ultimately, it will be necessary to get the largest number of vaccinations possible, to ensure a faster recovery and to limit further damage to the world.
CNN’s Harry Clark Ezidio, Jane Christensen, Maggie Fox, and Cara Fox contributed to the reports.